[IllinoisCoyoteHunter]

Taper crimps are not really meant to grip the bullet. They are used to iron out the flare that you put on to accept the bullet. This is why it is important to not flare excessively. As stated above by grumpa, under an excessive taper crimp, the bullet will swage and the brass will spring back a bit. When setting up my dies, I always make a dummy round and run it thru my pistol a couple times....measuring COL to make sure there is no bullet setback. Good luck.